In a jet engine, wherein a turbine rotor is mounted for rotation within an engine casing, it is common to provide a blade outer air seal (BOAS) between the casing and the turbine rotor so as to prevent or reduce leakage therebetween. Typically, the BOAS is mounted in the casing by way a bolted flange on the inner periphery of the casing. The purpose of the bolted flange is to accurately and reliably locate the BOAS and to provide effective sealing against the leakage of BOAS cooling air which is circulated on the radially outer side of the BOAS to cool and purge the BOAS.
Such a bolted flange assembly is relatively heavy, and ongoing efforts to reduce the weight of a jet engine favor the elimination of such a bolted flange. If the bolted flange is eliminated, however, an alternative approach to securing the BOAS in place, and for sealing against the leakage of cooling air, must be provided.